<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style> 
    img {
        width: 300px;
    }
</style>
</head>
<body>
  <div id="app">
      <button @click = 'changeImg'>点击更换图片</button>
      <hr>
      <img v-bind:src="src" alt="">
      <img :src="src" alt="">
  </div>
  <script src="./vue.js"></script>
  <script>
    var vm = new Vue({
      el:'#app',
      data:{
          src:"./img/1.png"
      },
      methods:{
          changeImg() {
              this.src = './img/2.png'
          }
      }
     });
  </script>
</body>
</html>
